Fuel injection filter system



May 12, 1959 J. DOLZA ET AL 2,886057 FUEL INJECTION FILTER SYSTEM FiledJune 12, 1957 IN V EN TORS HTTOlM/E) 2,886,057 3 FUEL nvrncrroiv FILTERSYSTEM 1 r John Dolza, Fenton, and WilliamH. Kolbe, Huntington Woods,Mich., assignors to General MotorszCorporation, Detroit, Mich., acorporation of Delaware Application June 12, 1957, sm ling. 665,299 b T3 Claims. rel. 137-434) The present device relates to a filter systemfor a fiiel injection system of the type shown in copending applica-2,886,057 Patented May 1 2, 1959,

. trolled lever 38 suitably pivoted at 48 to a bracket depending fromcover 30. Thus as the fuel level in the reservoir varies the flow offuel past the inlet valve 34 similarly varies in a well known manner.

The cover casing 30 is formed to provideacup -shaped receptacle 44 whichprojects ,within the fuel reservoir 14.

A filtering element 46 is disposed within the receptacle 44 and retainedtherewithin through a filter cover 48 which seats upon an upstandingwall 31 formed on cover 30. be

The fuel inlet passage 32 permits fuel to flow into the.

1 fuel receptacle 44 where it passes throughfilter 46 to flow tionSerial No. 608,853 Dolza, filed September 10,1956

and now Patent No. 2,843,098, issued July 15, 1958., ,I

In injection type fuel. systems fuel nozzles are utilized whichincorporate extremely small orifices thereinl As a consequence suchsystems are extremely vulnerable to malfunctioning due to the fouling orblocking up of such orifices. The meteringvalve in such system is alsovery susceptible to fouling by impurities carried" by the fuel stream. ij j It is a further necessity in a fuel injection system to prevent dirtof a particle size larger than the end clearance of the metering pumpfrom reaching the pump. Any such dirt particle is likely to becomelodged between the gears and end plate in such a way as to increase thepump end clearance and thereby reduce the pumps volumetric efiiciency.Accordingly, great caremust be taken in a fuel injection system toprovide suitable filtering means in advance of the points whereimpurities may impair the operation of a fuel injection system.

One of the most troublesome problems with such filtering systems hasbeen the inability to provide filtering elements which may be removed orreplaced without causing impurities to be set free in the system.

The present invention is directed to a filter device which providessatisfactory filtering of the fuel in the system and further whichfilter is capable of being removed from the system without danger oflosing impurities therein. The present filter is of the cartridge typewhich is disposed in the fuel metering casing and easily accessible forremoval purposes.

The details of the present invention as well as other objects andadvantages are set forth in the description which follows. b i

The drawing relates to a fuel injection system embodying the subjectfilter device.

The fuel injection system as such constitutes no part of the presentinvention and functions in the same manner as described in theaforenoted copending application. In general, a fuel metering unit isshown at 10 and includes a casing 12 within which a fuel reservoir 14 isformed. An engine speed responsive pump 16 is submerged in the fuelreservoir 14 and supplies fuel under pressure to a conduit 18 leading toa fuel metering valve 20. Metering valve 20 is controlled by a diaphragm22 suitably connected thereto through linkage 24 and which diaphragm isactuated in response to the mass of air flow through said system.Metered fuel from valve .20 is upwardly through a hollow portion50thereof to com municate with apassage 52 in cover 48.; Passage 52 inturn communicates with a downwardly extending passage 54. -A chamber 56is formed in reservoir cover 30 and. includes a secondary filter element58 disposed therein. The chamber 56 communicates with the passage 36lead-; ing to inlet valve 34. Thus, as the float controlled valve 34. isopened in response to a need for fuel in the reservoir, 14, fuel willflow through the inlet passage 32 into i the receptacle 44 through thefiltering element 46 passing supplied to conduits 26 which terminate innozzles 28 for delivery of fuel engine.

A casing 30 is adapted to. cover or enclose casing 12. A fuel inletopening'32 is provided in cover casing 30. A fuel inlet valve 34 isslidably disposed in cover casing 30 and is adapted to coact. with apassage 36 to control the admission of fuel into the reservoir 14. Theposition of the fuel inlet valve 34 is controlled by a float conto theindividual cylinders of the through passages 52 and 54 andsecondaryfilter 58.

. The filter element 46 comprises acylindrical. filtering element 60which is suitably connected, as by cementing, to an end plate 62.. Plate62 is fixed to an upstruck por tion or boss 64 of a cup-shaped casing66. The filter element 60 is thus supported within the casing 66 inspaced relation thereto. An upper end cap 68 is similarly fixed to thefiltering element 60 and includes an upwardly extending neck portion 70adapted to slide within a counterbore 72 of the filter cover 48.

The cup-shaped filter supporting casing 66 includes a radiallyextendingflange 74 adapted to seat upon a gasketed annular shoulder 76formedinternally of wall 31. A spring element 78 is adapted to seat against anannular seat 80 formed in cover 48 and bias upper end cap 68 downwardlycausing the flange 74 of the casing 66 to sit tightly against shoulder76.

With the filter 46 in position fuel will actually flow into be removedfrom casing 30 permitting the withdrawal of i the filter 60 and theintegral sediment catching casing 66. In this Way the filter may bechanged without any impurities being set free in the fuel system.Receptacle 44 provides a further safeguard against impurities enteringreservoir 14 during the change of filters.

The secondary filter 58 'is intended to intercept any microscopicparticles which may pass through filter element 60.

A conduit 80 communicates the metering valve 20 with a passage 82 incover 30 to return bypassed fuel to the reservoir 14.

We claim:

1. A fuel injection system comprising a casing, a fuel reservoir formedin said casing, a cover for said casing, a fuel inlet passage disposedin said cover, a fuel inlet valve movably mounted in said cover, a floatmechanism for controlling saidvalve mechanism in accordance with thefuel level within said reservoir, a receptacle formed in said cover, afilter device disposed in said receptacle, said device including acasing member supported upon said cover, a filtering element supportedby said casing and projecting therewithin, a cover for said filteringelement, said filter cover being adapted to be secured to saidcasingcover, said fuel inlet passage being adapted to deliver fuelwithin said filter casing whereby fuel will flow through said filteringelement, passage means formed in said filter cover, said cover passagemeans communi- 3 eating with said inlet valve whereby the filtered fuelflowing through said filtering element is conveyed to said fuel inletvalve, and a secondary filter intermediate said cover passage means andsaid fuel inlet valve.

2. A fuel injection system comprising a casing, a fuel reservoir formedin said casing, a cover for said casing, a fuel inlet passage disposedin said cover, a fuel inlet valve movably mounted in said cover, a floatmechanism for controlling said valve mechanism in accordance with thefuel level Within said reservoir, a receptacle formed in said cover andprojecting within said reservoir, a filter device disposed in saidreceptacle, said device including a cup-shaped casing member, a flangeon said member for supporting the member upon said cover, a filteringelement supported in radially spaced relation within said cas ng, acover having a counterbored portion for supporting said filteringelement, said filter cover being adapted to be secured to said casingcover, said fuel inlet passage communicating with said filter device todeliver fuel Within said filter casing permitting fuel to flow throughsaid filtering element, passage means formed in said filter cover, saidcover passage means communicating with said inlet valve whereby thefiltered fuel flowing through said filtering element is conveyed to saidfuel inletvalve, and a secondary filter intermediate said cover passagemeans and said fuel inlet valve.

3. A fuel injection system comprising a casing, a fuel reservoir formedin said casing, a cover for said casing, a fuel inlet passage disposedin said cover, a fuel inlet t 4 valve movably mounted in said cover, afloat mechanism for controlling said valve mechanism in accordance withthe fuel level within said reservoir, a receptacle formed in said coverand projecting within said reservoir, a filter device disposed in saidreceptacle, said device including a cup-shaped casing member, a flangeon said member for supporting the member upon said cover, a cylindricalfiltering element supported in radially spaced relation within saidcasing, a cover having a counterhored portion for supporting saidfiltering element, a pair of end plates fixed to said element, one endplate being fixed to a boss centrally formed in the closed end of saidcup-shaped casing, the other end cap including a longitudinallyextending neck portion adapted to project within the cover counterbore,spring means seating on said filter cover and biasing said casing flangeinto engagement with the casing cover, said filter cover being adaptedto be secured to said casing cover, said fuel inlet passagecommunicating with said filter device to deliver fuel within said filtercasing permitting fuel to flow through said filtering element, passagemeans formed in said filter cover, said cover passage meanscommunicating with said inlet valve whereby the filtered fuel flowingthrough said filtering element is conveyed to said fuel inlet valve.

References Cited in the file of this patent UNITED STATES PATENTSl,709,576 Hvoslef Apr. 16, 1929

